Dental polishing device.



W. L. HOUGH.

DENTAL POLISHING DEVICE.

APPLICATION FILED JUNE24. 1912.

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DENTAL POLISHING DEVICE.

Specification of Letters Patent.

Patented May 4, 1915.

Application led I une 24, 1912. Serial No. 705,385.

To all whom 'it may concern d Be it known that I, WILLIS L. HOUGH, a citizen of the United States, and resident of Laconia, in the county of Belknap and State of New Hampshire, have invented certain new and useful Improvements. in Dental Polishing Devices, of which the following is a specification.

This invention relates to attrition devices employed by dentists to polish the surface of teeth, fillings, crowns, etc., in the mouth of the patient. Such devices are employed in the form of disks to be rotated, and in the form of flexible strips.

For convenience of illustration andbrevi a dental attrition device which will not be affected by moisture and which will retain permanently a high degree of flexibility, resilience and strength, with the grit practically irremovable from the body. i The invention consists in the dental polishino' device, substantially as hereinafter described and claimed.

Of the accompanying drawings: Figure i 1 represents a perspective view of L polishing strip embodying my invention. Fig. 2 represents an enlarged section on line 2-2 of Fig. 1.

In carrying out my invention, a body layer of sheet celluloid a., a layer b of plastic material capable of hardening and of firmly uniting with the sheet celluuantity 0f grit c distributed over and su cientliy embedded in the layer b to not be remove by use.

A suitable material for the layer b may comprise celluloid dissolved or cut with alcohol, ether, Thisprovides a composition which is capa- I provide and bi-sulfid of carbon.

ble of hardening, and while doing so of being firmly united with the sheet celluloid layer a, and without in any way affecting or detracting from the flexibility, resilience, and strength or toughness possessed by said body layer a. In practice, the layer b is applied in any suitable manner, as by flowing it over or brushing it upon the body layer a and immediately the grit layer cis applied as by sifting the grit over the soft layer b. The grit immediately sinks sufficiently into the layer b, and the layer b begins to attach itself to the body layer a, and as the layer b hardens it firmly and durably unites the grit to said body layer. No heat or pressure is employed, and the body layer a is at no time rendered plastic.

When the grit c is distributed, the layer b solidifies and the grit is firmly attached to and practically becomes a part of the complete article.

As has been stated, it is essential that the complete article shall retain, practically complete, the characteristics of flexibility, resilience, and strength or toughness possessed by the body layer of sheet celluloid. Heat seriously affects all of these qualities, and to embed particles of grit in such body layer weakens the latter because of the numerous perforations or partial perforations. Particles cannot be embedded directly into sheet celluloid without subjecting the latter to heat, or to the action of a solvent, or both. After such treatment as last mentioned, celluloid never hardens to its original condition. Under my invention, however, the original condition of the body layer a which is depended upon for strength and resilience is never changed.

I claim A flexible dental attrition device comprising two celluloid layers intimately united to form a substantially homogeneous piece, one layer being continuous and unbroken, and grit embedded solely in the other layer.

In testimony whereof I have aflixed my` signature, in presence of two Witnesses.

WILLIS L. HOUGH.

Witnesses:

LE ROY M. KARNAN, JAMES A. PAYsoN, Jr. 

